The move by GM comes in direct response to a national outreach campaign organized by Forecast the Facts[2], which garnered more than 20,000 people, including 10,000 GM vehicle owners, calling on GM to drop its financial support of the Heartland Institute.

“We applaud GM’s decision and the message it sends: that it is no longer acceptable for corporations to promote the denial of climate change, and that support for an organization like Heartland is not in line with GM’s values. This victory belongs to the 20,000 Americans, including 10,000 GM owners, who demanded that GM put its money where its mouth is on climate change and sustainability,” said Forecast the Facts Campaign Director Daniel Souweine.

Climate One director Greg Dalton revealed the GM pullout[3] after receiving confirmation directly from GM during an event at San Francisco’s Commonwealth Club. Dalton had pressed GMCEO Dan Akerson about its support for Heartland at a Climate One event earlier this month. Akerson said at the time that he would personally review the Heartland funding.

Heartland President Joseph Bast was understandably upset[4] to learn of GM's decision to cease any further financial support, but continued to push his trusty shiny penny version of events rather than own up to the real reasons for the waning support of his group's efforts. Internal Heartland documents[5] made public last month exposed the shocking revelation of Heartland's plans to deceive schoolchildren about climate science, most notably.

GM was not the only automaker to fund the Heartland Institute: Ford and Chrysler also contributed to it in the past. Ford and Chrysler told The Huffington Post that they had stopped funding the organization over the past decade, but neither automaker had records detailing reasons for pulling that support.

It seems the Heartland Institute will have to continue relying on its “Anonymous Donor[6]” in order to keep up its desperate attacks on climate change science and scientists.

Most of its past corporate sponsors, including Koch Industries, have jumped ship from funding Heartland's climate denial efforts. Add Detroit's major car companies to the list of heart-breakers as well.